Tag Archives: exploit vector

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That vulnerability, according to a report on the data breach by William Baird & Co., was in a popular open-source software package called Apache Struts, which is a programming framework for building web applications in Java. Two vulnerabilities in Struts have been discovered so far in 2017. One was announced in March, and another was announced earlier this week on Sept. 4. At the moment, it’s unclear which vulnerability the Baird report was referring to.

The bug specifically affects a popular plugin called REST, which developers use to handle web requests, like data sent to a server from a form a user has filled out. The vulnerability relates to how Struts parses that kind of data and converts it into information that can be interpreted by the Java programming language. When the vulnerability is successfully exploited, malicious code can be hidden inside of such data, and executed when Struts attempts to convert it.

To exploit the flaw, Caballero says that an attacker can use server redirect requests combined with data URIs, which would allow him to confuse Edge’s SOP filter and load unauthorized resources on sensitive domains. The expert explains the attack step by step on his blog.

In the end, the attacker will be able to inject a password form on another domain, which the built-in Edge password manager will automatically fill in with the user’s credentials for that domain. Below is a video of the attack.

As you can see, it appears as Google Docs wants full access to my Gmail as well as my contacts. Of course, this is not real Google Docs – the attacker has simply named his “application” Google Docs – this can be verified by clicking on the Google Docs text where the real web site behind this and developer info is shown:

According to Scheel, the problem is that the HbbTV standard, carried by DVB-T signals and supported by all smart TVS, allows the sending of commands that tell smart TVs to access and load a website in the background.

Knowing this, Scheel developed two exploits he hosted on his own website, which when loaded in the TV’s built-in browser would execute malicious code, gain root access, and effectively take over the device.

An attacker can exploit the vulnerability by sending a malformed protocol-specific Telnet command while establishing a connection to the affected device, because of a flaw in how the protocol fails to properly process some commands.

Cisco said that there are “no workarounds” to address the vulnerability, but it said that disabling Telnet would “eliminate” some risks.

The (presumably ancient) code has a bug, though: it does not verify the syntax of the user name. RFC 959 specifies that a username may consist of a sequence of any of the 128 ASCII characters except <CR> and <LF>. Guess what the JRE implementers forgot? Exactly − to check for the presence of <CR> or <LF>. This means that if we put %0D%0A anywhere in the user part of the URL (or the password part for that matter), we can terminate the USER (or PASS) command and inject a new command into the FTP session.

So, if we send a USER command to a mail server instead of a FTP server, it will answer with an error code (since USER is not a valid SMTP command), but let us continue with our session. Combined with the bug mentioned above, this allows us to send arbitrary SMTP commands, which allows us to send emails.

The exploit ending in .flac works as a drive-by attack when a Fedora 25 user visits a booby-trapped webpage. With nothing more than a click required, the file will open the desktop calculator. With modification, it could load any code an attacker chooses and execute it with the same system privileges afforded to the user. While users typically don’t have the same unfettered system privileges granted to root, the ones they do have are plenty powerful.

Resolving all the above, I present here a full, working, reliable, 0day exploit for current Linux distributions (Ubuntu 16.04 LTS and Fedora 25). It’s a full drive-by download in the context of Fedora. It abuses cascading subtle side effects of an emulation misstep that at first appears extremely difficult to exploit but ends up presenting beautiful and 100% reliable exploitation possibilities.

The vulnerability, a variety known as a race condition, was found in the way Linux memory handles a duplication technique called copy on write. Untrusted users can exploit it to gain highly privileged write-access rights to memory mappings that would normally be read-only. More technical details about the vulnerability and exploit are available here, here, and here. Using the acronym derived from copy on write, some researchers have dubbed the vulnerability Dirty COW.

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